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Use previous time step solution in a function

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Hi all,

I want to build an external function solving some stuff by finite differences. I need to give the solution of the previous time step to my function. Do you know how to get these solution in COMSOL ? Is there something like Ut or Ux for the time or space derivative of U ?

I will also need the value of the time step.

I know I can do this using Matlab scripting, but the Matlab API is very very slow, so useless for optimization purpose.

Thanks a lot for your help !

Sébastien

2 Replies Last Post 3 Dec 2010, 01:35 GMT-5
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Hello Sébastien Janas

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Posted: 10 years ago 2 Dec 2010, 15:22 GMT-5
Hi,

I am wondering if you were able to solve the problem?

Ivan
Hi, I am wondering if you were able to solve the problem? Ivan

Ivar Kjelberg CSEM SA (CH)

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Posted: 10 years ago 3 Dec 2010, 01:35 GMT-5
Hi

check the 4.1 doc on the operator at(), with(), prev() and d(,)

there are a few threads on the Forum on different simple tricks how to get time derivatives for PDEs too

--
Good luck
Ivar
Hi check the 4.1 doc on the operator at(), with(), prev() and d(,) there are a few threads on the Forum on different simple tricks how to get time derivatives for PDEs too -- Good luck Ivar

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